Fixture Mount Occupancy Sensors: What Is The Maximum Thickness Of Metal For Mounting A FB3 Bracket?

The Sensor Switch FB3 bracket is a snap-in fixture mount bracket for lowering a fixture mount occupancy sensor such that its view is not impeded by the edge of the luminaire. Additional information available at the following - http://sensorswitch.com/DataSheets/FB3.pdf

The maximum thickness of metal in the fixture housing that it will snap-in is 0.70" thickness.